Rocket / Build

[pfarrell]

Ha! They weren't in stock at my bench... Should be here next week. All good! Waiting on a chassis too...and tubes. I wasn't planning on building 2x TW back to back.... I have a problem.

[pfarrell]

Any reason to not add a Type-2 MV to the Rocket out of the gate? I find it super good in the Express—and recently changed a Type-3 to Type-2 in my Vibroverb with excellent results—so much so that I love the amp all over again. Lowered the noise floor of the amp and it's a much more usable setup.

Also, what a gift the Trainwreck Pages are. Lots of good learning there.

AB763-VV_20.jpg

Type-2orLar-Mar_Master_Volume_Schematic.png

[pfarrell]

Case in the works... Might be a month or so until an OT shows up.

PF-TWRocket-03.jpg

[ChloeFree]

[aceofbones]

Nice. Looking good.
Waiting on parts is the worst part.

[gktamps]

I've put Lar-Mar masters on three of my Rocket type builds, and find that the tone and dynamics are negatively affected when adjusted past about 25%. Two of those builds also have VVR, and I've found a balance between a slight reduction in voltages combined with moderate use of the MV affect the tone the least, though it is still affected. I consider both to be a compromise to achieve lower volume when needed, and by no means an improvement to the sound of the Rocket.

[pfarrell]

Good info! I'll skip it for now... can always experiment later....

[pfarrell]

I was looking around for an OT since the Edcor will be a while, plus trying different OTs seems to be a thing I might want to play with as my knowledge/preferences grow... I came across a Pacific "PAM-OT-30-54R" (Originally "11415") listed as an OT for all three TW circuits... yet my research (documents abound on this forum) indicates dif secondaries on at least the Rocket—vs Express and Liverpool. The Pacific marketing states more or less "...this is what Ken used...". 7k5 secondaries on the Pacific OT...

thoughts on this?

[gktamps]

I disagree with Pacific.
See: https://ampgarage.com/forum/viewtopic.php?f=1&t=35103

[Colossal]

I also disagree with Pacific (and agree with gk ). If you watch the Matt O'Ree videos (sorry can't tell you or remember which one), Matt talks about a change to the output transformer used in the Express. He does not know the details either. My guess, and this is unproven, is that this may have been a change made by John Mark and is applicable to the lower wattage Trainwrecks. Just speculating on that, but I do not agree that the OT primary is 7k5 in the original TW amps.

[pfarrell]

So at present, based on the info in the forum—4K3 (or 5K2?) for Rocket builds—it seems that Edcor is the only place where one could reliably get iron (especially OTs) for these builds—not withstanding all the opinions about SQ and Edcor iron vs other brands. I emailed Edcor about iron part numbers I'd seen in other builds and was told they were custom built for RJguitars. Edcor got permission to list them on their site as of a couple of weeks ago...The original RJ part numbers are listed on the site—one of them I think is wrong based on the TW transformers spreadsheet I downloaded from the Files post(?).

I've used a lot of Edcor iron in Hifi builds, with no complaints—other than everything is built to order and thus takes about a month to get—and you have to be into blue bells—but I usually burn off the powdercoat and chemically blacken the raw steel. Put them head to head in some cases with the considerably more boutique offerings of Cinemag with great sounds all around... I put an Edcor OT in my Marshall since I happened to have it on hand... I think it sounds great—all subjective I'm sure.

[Colossal]

It is my understanding that a Dynaco A-470-S may have been used in the Rocket(s). I would contact RJ to see if he has any stock of his Heyboer-wound Dynaclone OTs. The A-470-S is 4k3 primary with a complex interleave.

[gktamps]

When I built my first Rocket, Allyn told me the Dynaco was not what Ken later used, though all OTs he used had 4k3 secondaries. Allyn did not elaborate beyond saying later transformers did not have the ultralinear taps. I built several using transformers bought from him, and they sound incredible. Still have a set waiting for one last build.

edited for clarity.

[aceofbones]

I would agree with Colossal. The OT I got from RJ for my Rocket is a Heyboer - modified Dynaco style. I"ll have to find the info, but the A-470-S that Colossal mentions rings a bell.

HTS-8093-1.jpeg

[ChloeFree]

Nice. Looking good.